In a humid and hot area, one-third of the cooling load of an air-conditioner is caused by the latent heat (heat which brings about a change of state with no change in temperature is called latent heat). In an area with sufficient solar radiation, one can design an air-conditioning system by utilizing the inexhaustible solar energy to solve the problems of high humidity and to save the electric power consumption.
Some conventional dehumidifiers do not utilize the solar energy to remove the moisture from humid air. Although some of them take advantage of the solar energy to evaporate the moisture absorbed by the liquid desiccant, they are generally too large and expensive. This is because they must be made large in size in order to attain more solar energy. So the conventional solar liquid desiccant systems are not popular in residential applications.
Therefore, the conventional dehumidifiers still have some drawbacks. The rate of condensation of the conventional dehumidifiers is lower, hence the air-conditioning system still consumes a large amount of electricity and is not economical.